Refer to our Texas Go Math Grade 4 Answer Key Pdf to score good marks in the exams. Test yourself by practicing the problems from Texas Go Math Grade 4 Lesson 8.5 Answer Key Area Multiply with Regrouping.

## Texas Go Math Grade 4 Lesson 8.5 Answer Key Multiply with Regrouping

**Essential Question**

How can you use regrouping to multiply 2-digit numbers?

Answer:

Area models help to multiply large numbers, in a simpler forms using multiplication box.

Explanation:

Show the problem as the area of a rectangle, and then break that rectangle into smaller chunks for easier solving.

This method is also known as box multiplication.

Next, multiply to find the area of each smaller rectangle.

For Example;

STEP 3 Add to find the product for the whole model.

So, 16 × 19 =304

(10 x 1 tens) ( 10 x 9 ones ) (6 x 1 tens) ( 6 x 9 ones )

( 10 x 10 ) ( 10 x 9) (6 x 10 ) ( 6 x 9 )

100 + 90 + 60 + 54 = 304

**Unlock the Problem**

By 1914, Henry Ford had streamlined his assembly line to make a Model T Ford car in 93 minutes. how many minutes did it take to make 25 Model Ts?

Answer: 2,3 25

Estimate: 2,700

Explanation:

By using place values and regrouping to find the estimate.

**Use place value and regrouping.**

Multiply. 93 × 25 Estimate. 90 × 30 = _________

So, 93 × 25 is 2,325. Since _________ is close to the estimate of ___________, the answer is reasonable.

Answer:

90 x 30 = 2700

So, 93 × 25 is 2,325. Since 2700 is close to the estimate of 2325, the answer is reasonable.

**Math Talk**

Mathematical Processes

Explain why you will get the same answer whether you multiply 93 × 25 or 25 × 93.

Answer:

It shows the Commutative Property.

Explanation:

Commutative property**: **The order of the factors does not change the product.

A x B = B x A

Let’s look at an example of the commutative property:

The result of multiplying 93 x 25 will be equal to multiplying 25 x 93. Although we change the order of the factors, the result is still 2325 .

Different Ways to Multiply You can use different ways to multiply and still get the correct answer. Shawn and Patty both solved 67 × 40 correctly, but they used different ways.

Look at Shawn’s paper.

So, Shawn’s answer is 67 × 40 = 2,680.

Look at Patty’s paper.

So, Patty’s also found 67 × 40 = 2,680

Question 1.

What method did Shawn use to solve the problem?

Answer:

Area models help to multiply large numbers, in a simpler forms using multiplication box.

Explanation:

Show the problem as the area of a rectangle, and then break that rectangle into smaller chunks for easier solving.

This method is also known as box multiplication.

Next, multiply to find the area of each smaller rectangle.

Question 2.

What method did Patty use to solve the problem?

Answer:

She used place values and regrouping methods.

Explanation:

We can multiply 2-digit numbers by multiplying and by finding each partial products such as the tens and ones separately, then add all partial products together.

**Share and Show**

Question 1.

Look at the problem. Complete the sentences.

Multiply ___________ and ___________ to get 0.

Multiply ___________ and ___________ to get 1,620.

Add the partial products.

0 + 1,620 = ___________

Answer: 1,620

Multiply 27 and 0 to get 0.

Multiply 27 and 60 to get 1,620.

Add the partial products.

0 + 1,620 = 1620

Explanation:

We can multiply 2-digit numbers by multiplying and by finding each partial products such as the tens and ones separately, then add all partial products together.

**Math Talk**

Mathematical Processes

Explain why you can omit zeros of the first partial product when you multiply 20 × 34.

Answer:

Multiply 34 and 20 to get 680

Add the partial products.

0 + 680 = 680

Explanation:

As zero has no value and when we multiply any number with zero the product is zero.

**Estimate. Then find the product.**

Question 2.

Estimate: ____________

Answer:

68 x 53 = 3,604

Estimate: 3,500

Explanation:

70 x 50 = 3,500

So, 68 × 53 is 3604.

Since 3,500 is close to the estimate of 3,604,

So, the answer is reasonable.

Question 3.

Estimate: ____________

Answer:

61 x 54 = 3294

Estimate: 3300

Explanation:

60 x 55 = 3300

So, 61 × 54 is 3,294.

Since 3300 is close to the estimate of 3294,

So, the answer is reasonable.

Question 4.

Estimate: ____________

Answer: 2,430

Estimate: 2,700

Explanation:

90 x 30 = 2700

So, 90 × 27 is 2430.

Since 2700 is close to the estimate of 2430,

So, the answer is reasonable.

**Problem Solving**

**Practice: Copy and Solve Estimate. Then find the product.**

Question 5.

34 × 65

Answer: 2,210

Estimate: 2100

Explanation:

Estimated values of 34 is 30 and 65 is 70

So, 30 x 70 =2100

Question 6.

42 × $13

Answer: $546

Estimate: $600

Explanation:

Estimated values of 42 is 40 and 13 is 15

So, 40 x 15 =600

Question 7.

60 × 17

Answer: 1,020

Estimate: 1200

Explanation:

Estimated values of 17 is 20

So, 60 x 20 =1200

Question 8.

62 × 45

Answer: 2,790

Estimate: 3000

Explanation:

Estimate values of 62 is 60 and 45 is 50

So, 60 x 50 = 3000

Question 9.

57 × $98

Answer: $5,586

Estimate: $6000

Explanation:

Estimate values of 57 is 60 and 98 is 100

So, 60 x 100 = 6000

Question 10.

92 × $54

Answer: $4,968

Estimate: $4,500

Explanation:

Estimate values of 92 is 90 and 54 is 50

So, 90 x 50 = 4500

Question 11.

75 × 20

Answer: 1,500

Estimate:1,500

Explanation:

Estimate value 75 x 20 = 1500

As they are already rounded to the nearest tens.

Question 12.

66 × 55

Answer: 3,630

Estimate: 4,200

Explanation:

Estimate value of 66 is 70 and 55 is 60

So, 70 x 60 = 4200

Question 13.

73 × $68

Answer: $4,964

Estimate: $4900

Explanation:

Estimate value of 73 is 70 and 68 is 70

So, 70 x 70 = 4900

Question 14.

72 × 40

Answer: 2,880

Estimate: 2800

Explanation:

Estimate value of 72 is 70

So, 70 x 40 = 2800

**Unlock the problem**

Question 15.

**H.O.T. Multi-Step** Analyze Machine A can label 11 bottles in 1 minute. Machine B can label 12 bottles in1 minute. How many bottles can both machines label in 15 minutes?

(A) 165

(B) 180

(C) 245

(D) 345

Answer:

Option(D)

Explanation:

Machine A can label 11 bottles in 1 minute.

Machine B can label 12 bottles in 1 minute.

Total bottles in 1 minute = 11 + 12 = 23

Total bottles can both machines label in 15 minutes

23 x 15 = 345 bottles.

a. What do you need to know?

Answer:

I need to know total number of bottles can both the machine label in 15 minutes.

b. What numbers will you use?

Answer:

I will use 11, 12 and 15 numbers.

c. Tell why you might use more than one operation to solve the problem.

Answer:

To find the total number of bottles can both the machine label in 15 minutes.

d. Solve the problem.

Answer:

Total bottles A + B = 11 + 12 = 23

Total bottles can both machines label in 15 minutes

23 x 15 = 345 bottles.

e. Fill in the bubble for the correct answer choice above.

Answer:

Option(B) is the correct answer choice above.

**Daily Assessment Task**

**Fill in the bubble completely to show your answer.**

Question 16.

A polo team is making 18 mallets from cane. Each mallet is 84 inches long. How many inches of cane do they use?

(A) 1,512 inches

(B) 756 inches

(C) 1,482 inches

(D) 1,412 inches

Answer:

Option(A)

Explanation:

A polo team is making 18 mallets from cane.

Each mallet is 84 inches long.

Total inches of cane they use

18 x 84 = 1,512 inches.

Question 17.

A principal purchases 68 e-readers for $79 each. How much does the principal pay for the e-readers?

(A) $1,088

(B) $4,802

(C) $5,372

(D) $4,372

Answer:

Option(C)

Explanation:

A principal purchases 68 e-readers for $79 each.

Total amount paid by the principal for the e-readers.

68 x 79 = $5,372

Question 18.

**H.O.T. Multi-Step** There are 13 students in the sticker club. Each student puts 6 stickers on each of 34 pages in their scrapbook. How many stickers are in all of the scrapbooks?

(A) 546 stickers

(B) 2,652 stickers

(C) 2,322 stickers

(D) 2,312 stickers

Answer:

Option(B)

Explanation:

There are 13 students in the sticker club.

Each student puts 6 stickers on each of 34 pages in their scrapbook.

Total stickers in each scrap book 34 x 6 = 204

Total stickers in all of the scrapbooks

204 x 13 = 2,652 stickers.

**Texas Test Prep**

Question 19.

A toy company makes wooden blocks. A carton holds 85 blocks. How many blocks can 19 cartoons hold?

(A) 1,615

(B) 1,575

(C) 1,515

(D) 850

Answer:

Option(A)

Explanation:

A toy carton holds 85 blocks.

Number of blocks can 19 cartoons hold

85 x 19 = 1,615 blocks

### Texas Go Math Grade 4 Lesson 8.5 Homework and Practice Answer Key

**Estimate. Then find the product.**

Question 1.

Estimate _________

Answer: 3,404

Estimate: 3,500

Explanation:

Estimates of 74 is 70 and 46 is 50

70 x 50 = 3,500

So, 73 × 46 is 3504.

Estimate 3,500 is close to the product 3,404

So, the answer is reasonable.

Question 2.

Estimate _________

Answer: 364

Estimate: 300

Explanation:

Estimates of 28 is 30 and 13 is 10

30 x 10 = 300

So, 28 × 13 is 364.

Estimate 300 is close to the product 364

So, the answer is reasonable.

Question 3.

Estimate _________

Answer: 1,625

Estimate: 2,100

Explanation:

Estimates of 65 is 70 and 25 is 30

70 x 30 = 2,100

So, 65 × 25 is 1,625.

Estimate 2,100 is close to the product 1,625

So, the answer is reasonable.

Question 4.

Estimate _________

Answer: 608

Estimate: 600

Explanation:

Estimates of 19 is 20 and 32 is 30

20 x 30 = 600

So, 19 × 32 is 608.

Estimate 600 is close to the product 608

So, the answer is reasonable.

Question 5.

Estimate _________

Answer: 1,494

Estimate: 1,600

Explanation:

Estimates of 83 is 80 and 18 is 20

80 x 20 = 1,600

So, 83 × 18 is 1,494.

Estimate 1,600 is close to the product 1,494

So, the answer is reasonable.

Question 6.

Estimate _________

Answer: 2,880

Estimate: 2,800

Explanation:

Estimates of 72 is 70 and 40 is already rounded to its tens place.

70 x 40 = 2,800

So, 72 × 40 is 2,880.

Estimate 2,800 is close to the product 2,880

So, the answer is reasonable.

**Problem Solving**

Jill can make 14 origami boxes in an hour. Nathan can make 17 origami boxes in an hour. How many boxes can both of them make in 12 hours?

Question 7.

What do you need to know?

Answer:

I need to find number of boxes both can make in 12 hours.

Question 8.

What numbers will you use?

Answer:

Numbers used are 14, 17 and 12.

Question 9.

Tell why you might use more than one operation to solve the problem.

Answer:

Yes, more than one operation is required.

Explanation:

First we have to find the total number of boxes made by them in 1 hour.

Then total number of boxes made in 12 hours.

Question 10.

Solve the problem.

So, both people can make ________ boxes in 12 hours.

Answer:

Both can make 372 boxes.

Explanation:

Jill can make 14 origami boxes in an hour.

Nathan can make 17 origami boxes in an hour.

Total boxes both can make in 1 hour 14 + 17 = 31

Number of boxes both make in 12 hours

31 x 12 = 372 boxes

**Lesson Check**

**Fill in the bubble completely to show your answer.**

Question 11.

Bags of lemons weigh 33 pounds each. What is the total weight of 46 bags of lemons?

(A) 1,308 pounds

(B) 1,518 pounds

(C) 1,508 pounds

(D) 1,418 pounds

Answer:

Option(B)

Explanation:

Bags of lemons weigh 33 pounds each.

The total weight of 46 bags of lemons

46 x 33 = 1,518

Question 12.

Health club membership costs $65 a month. How much does a membership cost for 12 months?

(A) $770

(B) $690

(C) $780

(D) $775

Answer:

Option(C)

Explanation:

Health club membership costs $65 a month.

Total membership cost for 12 months

12 x 65 = $780

Question 13.

There are 19 players on a baseball team. Uniforms cost $74 each. How much will uniforms for the team cost?

(A) $1,406

(B) $1,376

(C) $1,216

(D) $1,306

Answer:

Question 14.

Jason bought 39 boards that are each 12 feet long. How many feet of lumber did he buy?

(A) 458 feet

(B) 358 feet

(C) 368 feet

(D) 468 feet

Answer:

Option(D)

Explanation:

Jason bought 39 boards that are each 12 feet long.

Total feet of lumber he bought

39 x 12 = 468

Question 15.

**Multi-Step** Owners of a summer camp are buying new cots for their cabins. There are 16 cabins. Each cabin needs 6 cots. Each cot costs $92. How much will the new

(A) $8,742

(B) $9,022

(C) $8,722

(D) $8,832

Answer:

Option(D)

Explanation:

There are 16 cabins.

Each cabin needs 6 cots.

16 x 6 = 96

Each cot costs $92.

Total cost of 16 cabins

96 x 92 = 8,832

Question 16.

**Multi-Step** A theater has 28 rows of 38 seats downstairs and 14 rows of 26 seats upstairs. How many seats does the theater have?

(A) 1,428

(B) 1,228

(C) 1,408

(D) 1,208

Answer:

Option(A)

Explanation:

A theater has 28 rows of 38 seats downstairs

28 x 38 = 1,064

14 rows of 26 seats upstairs.

14 x 26 = 364

Total seats the theater have 1,064 + 364 = 1,428